Blowing Cosmic Bubbles

This NASA Hubble Space Telescope image
reveals an expanding shell of glowing gas surrounding
a hot, massive star in our Milky Way Galaxy. This
shell is being shaped by strong stellar winds of
material and radiation produced by the bright star
at the left, which is 10 to 20 times more massive
than our Sun. These fierce winds are sculpting the
surrounding material - composed of gas and dust
- into the curve-shaped bubble. Astronomers have
dubbed it the Bubble Nebula (NGC 7635). The nebula
is 10 light-years across, more than twice the distance
from Earth to the nearest star. Only part of the
bubble is visible in this image. The glowing gas
in the lower right-hand corner is a dense region
of material that is getting blasted by radiation
from the Bubble Nebula's massive star. The radiation
is eating into the gas, creating finger-like features.
This interaction also heats up the gas, causing
it to glow. Scientists study the Bubble Nebula to
understand how hot stars interact with the surrounding
material.